多光子纠缠操纵研究

As an important resource for quantum information processing, quantum entanglement is closely related with many quantum information tasks. It is a great challenge to efficiently increase the number of entangled qubits. Thus, to generate and manipulate multi-entangled qubits became fiercely competitive internationally. So far, up to 14 entangled qubits were produced in the ion trap system and 8 phonton entanglement was realized in the linear photonic system. This proposal will keep on moving along the two directions of more photons entanglement and hyperentanglement to study on the multiphoton entanglement manipulation. We will try our best to make a breakthrough. We will develop a new technique to generate entangled photons with more brightness and visibility, further to generate 10 entangled photons. At the same time, we will introduce the degree of orbital angular momentum into previous hyperentanglment to coherently control 12-18 photonic qubits. Next, we will study the application in quantum computer, quantum simulation and novel quantum principle test with these new entangled sources. The research of multiphoton entanglement and manipulation is fundamental and prospective. To efficiently generate and manipulate more entangled qubits will not only enhance the scalability of linear optical system, but also be hopeful to supply academic foundation for scalable quantum information processing technique.

作为量子信息至关重要的一种资源，量子纠缠的研究非常重要，多个纠缠量子比特的制备与操控一直都是国际上竞争非常激烈的研究领域。迄今为止，最多的纠缠量子比特是囚禁离子系统中的14个，而对于线性光学系统而言，目前的世界纪录是8光子纠缠。本项目将围绕纠缠更多光子和在光子多个不同自由度之间构建超纠缠这两个方面展开系统性研究，努力打破现有纪录。我们将制备高亮度、高对比度的新一代纠缠光源，实现10个独立光子的纠缠；另外，将引入光子的轨道角动量自由度，完成对于单光子极化、路径、轨道角动量3个自由度的同时操控，实现12-18比特超纠缠；并更进一步探索新型纠缠技术在众多量子信息处理任务中的应用。开展多光子纠缠操纵的研究，具有很强的基础性和前瞻性，进一步高效地制备和操控更多的光子比特，将会大大增强线性光学的可扩展性，有望为构筑下一代可升级的量子信息技术奠定坚实的基础。

本项目围绕多光子纠缠操纵，开展系统研究，完成了各项既定目标，取得一批国际领先的科研成果：首次实现多自由度量子隐形传态，被英国物理学会旗下的《物理世界》选为2015国际物理学年度突破，这是历史上在中国本土完成的科学成果首次入选《物理世界》评选的国际物理学年度突破；首次实现十光子纠缠，刷新了光子纠缠态制备的世界纪录；通过调控光子极化、路径和轨道角动量，首次实现可独立调控的十八比特量子纠缠，创造了所有系统新的量子纠缠纪录；首次实现可扩展量子中继器的光学演示；首次实现高容错嵌套薛定谔猫态；首次实现机器学习量子算法的演示验证；首次实现基于经典指令的量子云计算演示等。共发表SCI论文16篇，项目负责人以通讯作者身份发表Nature Photonics 1篇，Physical Review Letters 2篇，Physical Review A 3篇；以共同指导者身份发表Nature 1篇，Nature Photonics 1篇，Physical Review Letters 5篇，Optica 1篇，Physical Review A 2篇。